(19)

(11)

EP 0 686 076 A1

(12)

(43) Date of publication: 13.12.1995 Bulletin 1995/50 (21) Application number: 94909651.0 (22) Date of filing: 17.02.1994

(51) International Patent Classification (IPC):  B24B 37/ 04( . ) (86) International application number: PCT/US1994/001675 (87) International publication number: WO 1994/019153 (01.09.1994 Gazette 1994/20)

(84) Designated Contracting States: DE GB IT (30) Priority: 23.02.1993 US 19930021215 (71) Applicant: MEMC Electronic Materials, Inc. St. Peters, Missouri 63376 (US)	(72) Inventors: LEONI, Fabrizio St. Peters, MO 63376 (US) MORGANTI, Marco St. Peters, MO 63376 (US) VESCO, Luigi St. Peters, MO 63376 (US) (74) Representative: Eyles, Christopher Thomas  W.P. THOMPSON & CO. Celcon House 289-293 High Holborn London WC1V 7HU London WC1V 7HU (GB)